This proposal requests funds to assist in the support of the second biennial Gordon Research Conference on Hormonal Carcinogenesis to be held in the New Hampton School, New Hampshire, August 2-7, 1987. This meeting is to bring together a series of multidisciplinary experimental systems that are related by the common goal of understanding the cell proliferative and carcinogenic activities of hormones at the cellular and organismal levels in endocrine organs and target tissues. This will provide an opportunity for a diverse group of basic scientists to share their new ideas and data in informal discussion and enquiry during the week of this conference. The most disturbing property of some steroidal and nonsteroidal hormones, particularly estrogens, is their carcinogenic activity. In an effort to address this problem, which is of increasing concern, the following session topics will presented in our upcoming Conference: (1) Hormone Associated Human Cancers - dealing with carcinogenic aspects of intrauterine exposure to DES and hormones, carcinogens and endometrial cells; (2) Differentiation and Transplacental carcinogenesis - dealing with transplacental exposure to DES and mammary development and carcinogenesis and specificity of oncogene activation in carcinogen-induced tumors is related to host development; (3) Culture Models for Cell Proliferation - dealing with role of transforming growth factors in epithelial cell systems, estrogen and antiestrogen regulated secretion of growth factors in human breast cancers and prolactin growth factors, and mammary cancers; (4) Growth Factors and Oncogenes - dealing with cellular and molecular mechanisms of estrogen induced cell transformation and steroid hormone receptors and control of gene expression in breast cancer; (5) Stages in Hormonal Carcinogenesis - dealing with histogenesis of estrogen-induced renal carcinomas in the hamster and estrogen promotion of hepactcarcinogenesis in rats; (6) Bioactivation and Irreversible Binding - dealing with regulation of estrogen bioactivation and metabolism and bioactivation of estrogens and DNA damage in Syrian hamster kidney; (7) Role of P-450 in Steroid Hydroxylation - dealing with catechol estrogen formation: a plethora of phenomena, hepatic cytochromes P-450: regulation of endogenous steroid metabolism and covalent estrogen binding to specific hamster cytochrome P-450's: possible consequences; (8) Androgen Carcinogenesis - dealing with combined androgen-estrogen- induced hyperplasia and dysplasia in the rat dorslateral prostrate and steroid induced tumors arising in the male Syrian hamster reproductive tract: regulation of tumor growth by autocrine mechanism.